5 Factors That Determine Ceiling Fan Airflow

There are many factors to consider when you’re shopping for a ceiling fan. You want the right size fan that serves the purpose of each room and perfectly matches the décor, but your first priority should be the motor. The motor determines the power, performance, and longevity of a fan. Ceiling fan airflow and efficiency are often overlooked, but the amount of air your fan moves each minute impacts the level of performance.

Five factors work together to determine the airflow and efficiency of a ceiling fan: blade pitch, blade shape and size, RPM, height from ceiling, and motor size. By paying attention to the ways in which these factors affect one another, you can buy a ceiling fan that fits your needs and has long-lasting durability without noise or wobble.

Understanding the Five Factors of Ceiling Fan Airflow

Blade Pitch

Blade pitch refers to the angle of the blades as they move through the air. Picture a ceiling fan’s blades as the oars of a rowboat. When the blades are flat to the surface of the water it doesn’t take much force to move them. Then, as you tilt the blades at a steeper angle, it becomes progressively harder to row the boat. If you don’t increase your force, you can work harder without being able to move faster or cover as much distance.

This applies to ceiling fan airflow as well. Fan blades with a relatively flat pitch—between 10 and 12 degrees—do not require a very large motor to reach a high speed. A steeper blade pitch, such as 14 to 15 degrees, will require a more powerful motor to achieve the same speed. Even at a high speed, the fan with the flatter pitch will move less air and may wobble or make noise due to being overworked. On the other hand, the fan with the steeper blade pitch may wear out much faster if the motor isn’t powerful enough to move larger amounts of air for longer periods of time.

Bottom line: The pitch of the blades and the power of the motor need to complement one another. If they work against each other, your fan will have to work much harder to move less air, resulting in less comfort and a motor that burns out faster—which is why quality ceiling fan manufacturers always design and test to make sure motors and blades work together well.

Blade Shape and Size

Blades cannot be too long or too wide if you want to maximize ceiling fan airflow. Bigger does not necessarily mean better even if the fan has a large motor. Larger and wider blades may not be able to move as much air, but blades that are too small and narrow can have a similar effect. Speak with a ceiling fan expert to ensure the motor and blades will work together properly.

RPM

RPM refers to how fast the blades spin at a specific speed. The faster the blades spin the more air they move, but only if the blades have the right pitch. Ideally, to achieve the best ceiling fan airflow, you want to buy a fan that has six separate speed settings ranging from low to very high.

Height from Ceiling

Your ceiling fan’s blades need to be at about 10 to 12 inches from the ceiling to produce the best airflow. Unless it is a hugger ceiling fan that is designed to be closer to the ceiling, if your typical fan is too close or too far from the ceiling it won’t move as much air. If you have vaulted ceilings you’ll want to add a longer downrod so the blades are about 8 to 9 feet from the floor.

Motor

The motor is the most important feature on your fan, provided that the other four factors are working in alignment. You can always count on the most powerful motors to provide excellent ceiling fan airflow, comfort, and durability. Although they can be more expensive, a high-powered fan will deliver the best return on investment and ultimately have a longer life.

When all five of these factors work together as one you can be sure to achieve the best performance, airflow, and efficiency. Since there are so many variables involved with ceiling fan airflow, you will want to consult a ceiling fan expert to help you choose the perfect fan your space. Talk to a professional today by visiting www.CeilingFan.com or calling 877.724.2326.

Sorry for the delay in responding to your gracious compliment. We’ve been pretty busy this summer as more and more people learn what ceiling fans can do for them and their family. My manager reminded me of your encouragement. So today, I say a big THANK YOU!

Thanks again…. and as you said to me, I say to you, “have a great afternoon” and a cool one at that.

I need a fan to circulate air in my home. We have a open concept living room. With 25 foot ceilings and the loft bedroom is upstairs. I want to circulate air for winter and summer since we live in Alaska and oil heat is very expensive. How far down should I place rod? What size motor, blade pitch? I am so confused and no one really is on the same page with me. Help and thank you

Hi Kris,
I ran your question by our sales manager. His first question was which room you were primarily trying to heat and cool. Each fan has a cone of air coming down from the blades, so, if you want to primarily cool the Loft you would hang the fan high so that the cone of cool air will come down into the Loft. This air would still reach your Living Room if your fan motor is strong enough, but it would be somewhat dissipated by then. For heating purposes, running the fan in reverse on slow speed will push the warm air from the ceiling, down the walls, and into the Loft. It will also push the warm air down into the main room, but the air will probably be cooled by the time it reaches the floor level.

If you’d rather focus on cooling and heating the Living Room, you’d want to place your fan about 10’ above the floor. However in this case the cool air circulated probably won’t reach your Loft.

Another thing to consider is that most downrods come in 6 foot maximum lengths. You can overcome this with downrod couplers, but not all manufacturers have these. Focus on Minka Aire, Fanimation, and Emerson if you want to hang your fan more than 6 feet below the ceiling.

Probably the main issue you’ll want to consider is the size of the motor. For your situation we would recommend a powerful motor and steeply pitched blades. Both the Emerson K55 motor and the Casablanca XLP are powerful motors with rubber flywheels to limit the wobbling which would be exaggerated with long downrods.

Another option you may want to consider for cooling both rooms is to drop the fan into the lower room and run the fan in reverse on high speed giving a wind chill effect (which is what cools you). High speeds push the air back up to the ceiling and down the walls, still cooling but without the breeze directly on you.

Unusual room configurations often require a personal consultation. Feel free to call us at 877-724-2326.

Oh dear… Speaking from the science of pitch props, this has a lot to be desired.
Determining motor size to fan pitch and diameter is not rocket science. The article makes it sound like the manufactures are “guessing” the correct ratios.

I totally agree that it is wise to stick with name brand manufacturers. They design their blades (many of them quite artful and different) to work with the motors they’re bundled with. Check out the unusual blades on the Fanimation Avaston or the Minka Aire Artemis.

I didn’t realize there were so many variable to choosing the best ceiling fan for our home. We live in Alaska and many home are heated with wood or oil stoves but are not efficient in moving air. Many homeowners use ceiling fans to move the air in the house and keep the heating cost down.

Since we have a low ceiling, we will definitely be contacting you when we are ready to purchase our next ceiling fan.

My husband has a painting studio in a garage that is 25 x 20 x 20 feet high. The heating source is mounted at the top facing into the room at a downward angle. What kind of ceiling fan will push the heat down to the floor to keep the room warm during the winter?

Optimally, two fans are ideal for that size room. Putting the fans down on a 4-6 foot pole, depending on your personal preference, should work well, as long as the fan has a large motor and high cubic feet per minute air movement. This you can see on the CFM shown for every fan on our site, like the one shown here.

Emerson has fans specifically designed for heating, called the Emerson heat fans, or if you don’t like the look, then you can use any indoor fan, as long as it moves air well. Just put it in reverse, clock-wise, so that it moves the cool air up, and the warm air down.

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what I’m looking for. can you offer guest writers to write
content to suit your needs? I wouldn’t mind writing a post or
elaborating on some of the subjects you write regarding here.
Again, awesome web site!

I am making a studio (ceramics) over our garage, and want to install 2 ceiling fans. The space is about 25′ x 25′, with 12-14′ ceilings.. I love the industrial look– Westinghouse makes a 52″ fan, Home Depot #7861400, in brushed nickel that looks terrific and moves a lot of air. However it doesn’t reverse. Is it possible to 1. wire it to reverse; 2. find a like model that does reverse; or 3. does it really make a difference?! I’m in steamy summers freezing winters new england. The heat source is a heat exchanger.

Unfortunately, that Westinghouse fan does not reverse, and cannot be wired to reverse. However, the Craftmade Mondo ceiling fan does reverse, and comes with six speeds to boot. The 54″ version of the Mondo looks similar to the Westinghouse that I think you were referring to. Reversing definitely does help with heat distribution in winter, helping all that rising warm air come back down where you can feel it.

Thanks for your question! I’d love to answer any others you have. 🙂
If you’re interested in the Craftmade Mondo or any other fans, feel free to give us a call at (877) 724-2326.

just bought a hunter fan but the high setting doesn’t seem as high as it should…it seems like the medium to low setting on most ceiling fans I’ve had. what should I have looked for? I’ve never seen any difference before this fan. thanks

It can be difficult to determine fans with the best airflow without experience with many fans (one reason why we often suggest people call and speak to our salesmen who have been selling nothing but ceiling fans for years).

However, each fan on our site has an indicator of Airflow called CFM or Cubic Feet per Minute. It is the first element on the Energy Label on all fans on our site:

Also, to help find fans with high airflow we’ve added an Airflow CFM filter. To use it start at http://www.ceilingfan.com/All-Ceiling-Fans-s/31.htm, scroll toward the bottom of the page to find the Air Movement (CFM) menu selection and click on the link to the highest CFM (8000+) to see all of our highest air movers.

Hi Kathy,
The clicking is not from the motor, it is likely caused from loose screws so I recommend tightening your blade holder screws and set screws first. If the problem continues, have an in-home service technician come to diagnose the problem.

Hello,
We have 2 ceiling fans – both with the same CFM of 6000. One fan was installed by the builder – a professional series. The other we bought in a retail hardware store. They both are installed at about the same height from the ceiling. However, the air flow in the professional series “seems” to be better than the one from the retail store. What other indicator or features do we need to look at when buying a ceiling fan? Also, how to tell for sure the speed of the fan other than the feel of the cool breeze?

There are a lot of variables that can affect the air efficiency, including installation. Are the room ceiling heights different? Are the rooms the same size? Does one room have a ceiling slope to account for? As you can see, there are a lot of factors to consider. It’s important to choose the best ceiling fan for your room and your needs. We have a Buyer’s Guide that can help you when choosing a ceiling fan, as everyone’s needs are different. Check it out here: http://www.ceilingfan.com/Buyers-Guide-s/1705.htm

I apologize for the delayed response. If the air is blowing upward instead of down, it appears that you have your fan in the winter heat setting, which means the blades are moving clockwise. The fan blades need to be moving counter-clockwise for the summer setting, pushing air downward.

The quantity of blades doesn’t affect airflow, but it can affect the sound of the fan. Fewer blades (3 for instance) can produce a strong airflow, but they can also have a choppy sound as they move the air. When a ceiling fan makes a helicopter sound, this is why. More blades make the sound less noticeable to near-silent. If you have any other questions, I’d be happy to help.﻿

sir am an electrical engineer student we are making a efficient ceiling fan for that we are using brushless dcmotor .problem is we want to make best air flow out of it how we select size of blades.how to make best out of it.plz provide me every data

This seems like more of an engineering question which is a bit out of our realm. There are things to consider that affect air efficiency and this is a good video that goes over the key parts: https://youtu.be/_IH78QEjrqE

I have a big problem with a big fan. I have built a ceiling fan for out side use witch is 147 inches tip to tip it has. 1hp motor which turns 1750 rpm and a gear reduction that brings down to 90 rpm my blades are 60 inches long and 8 inches wide toward the center and 16 inches wide toward the outside and there are 8 blades the fan is mounted about 12 to 14 inches from the ceiling . It runs great no wobble or anything . The problem is there is no downward air flow . I started out at 22.5 degree and the went to 30 degree. This put a big strain on my motor and still no air flow. I then took 4 blades off and set the remaining 4 at 10 degree . My motor loved that set up but still no airflow. I was wondering what I’m doing wrong . Any help or comments would be greatly appreciated .
Thank you in advance for your help.

First off, I’m impressed that you built a fan on your own! That’s a first! Our fans have been engineered and quality tested to perform at high quailty. Perhaps you can contact a ceiling fan manufacturer and ask to speak to their engineering department to further assist you as this is a bit out of our realm. Best of luck!

Help! I know what I would like but can’t seem to find all of my requirements at a price this senior lady can afford, and have been searching for months so your time, effort, and instructions will sincerly be appreciated.
I am looking for a energy star efficient, 50″ brushed nickel, ceiling hugger, 5 13* pitch, medium wood color fan blades, reversible 3 speed fan, with a bowl type lighting fixture that is LED compatible, that also can be remote controled for dimming lights and fan speed…….Wheeeew! Again, thank you for your help!
Char

We have a slanted ceiling – about 16 Ft on one end, 20 ft on the other. The wood stove is one corner on the 16 ft side. The room itself is about 20 by 20, maybe a little larger. There are already 3 overhead lights in the ceiling, evenly spaced from the wood stove to the top corner of the room, about 5 feet from the outside wall. I was hoping to replace one of the lights with a ceiling fan to distribute the heat down to the room. That way, we wouldn’t have to do any sheetrock work, keeping our costs down. What do you think the viability of that is? Since the lights are on the side of the room, would we need another ceiling fan somewhere else? Would we need to forgo the light idea and just install a fan in the middle of the room? Your input would be much appreciated.

If you are wanting to avoid new electrical installation costs, then installing a ceiling fan where there is already electricity is a possibility, although you still need to make sure you have a fan approved junction box. You will also need to make sure you have the correct sized down rod and blade size to avoid hitting the wall or a strobe effect from being too close to the other lighting.